Introduction

A bstract : In The Expression of Emotions in Man and Animals Darwin argued that emotions are not unique to humans, but can be found in many species; that many of the same social occasions that generate emotions in humans do so in other animals. He asked why this particular expression for a particular emotion, and his answer formed part of his demonstration of the continuity of the species and was thus crucial to his evolutionary theory. Darwin was one of the first scientists to use photographs as illustrations and to use the judgment method for studying the signal value of an expression—which has become the most frequently used method in the psychology of expression. The contents of the present volume extend, support, and sometimes contradict Darwin's remarkable contribution to the field of the expression of emotions.